Method of applying magnetic material to electrical conductors



June 1 1926.

1,586,862 w. B. TEN EYCK 'METHOD OF APPLYING MAGNETIC MATERIAL T0 ELECTRICAL CQNDUCTORS Original vFiled 8. 1920 Patented June 1, 1926.

UNITED srra \K ILLIADI B. TEN EYCK, OF BLOOMFIELD, NEW JERSEY, ASSXGNOTR. '10 ti ES'IEEjt-I 1E.- TRIC COMPANY, INCORPORATED, OF NEW YORK. N. L, A COBIEOLRA'I'ION 031' hi.

YORK.

METHOD OF APPLYING MAGNETIC MATERIAL TO ELECTRICAL CQNDUCTfiE-fz.

Application filed December 8, 1920, Serial No. 129,22 1. Renewed April 10, 1926.

This invention relates to the application of magnetic \vrapping's to electrical conductors, and particularly to the manufacture of continuously loaded signaling conductors.

An objeet ol' the invention is to provide a method by which signaling conductors may be continuously loaded and a predetermined permeability at low magnetizing forces in the magnetic material he realized.

In carrying out the above noted object there is preferably applied to the signaling conductor or conduetors a""n1a;rnctic sheath in the form of a layer or layers of tape wound spirally thereon. A suitable magnetic material is the nickel iron alloy do scribed in the U. S. application of t}. \V. lllmen, Serial No. 473,877, tiled May 2- 1921, which ;is a continuation of applieation, Serial No. 111,080, tiled July 21-, 1916. This material has the requisite of high permeability only when properly heat treated. and not subsequently subjected to excessive strain. It was found that the strainsset up in this loading material by applying it to the conductor were sullicient to lower the permeability and that this dilliculty could be overcome by applying proper heat treatment to the loaded conductor. See the Elmen application referred to above and also application, Serial No. 557,928, tiled May 2, 1922, of the same inventor.

Diliiculty has been experienced however-in obtaining the desired high value of per meability in the loading material at low magnetizing forces when the above described process is used. According to the present invention this difiiculty is overcome by cov' eri'ng the signaling conductor with a layer of spacing material before the loading material is applied, the spacing material being of papc'r, linen, cotton, or Woolen fabric, gums or other material of a nature to be removed before or during the heat treatment.

In carrying out the process, the conductor is first covered with the spacing material which is preferably paper tape laid on the conductor spirally. The magnetic material in the form of tape is then laid spirally over the spacing material.

The arrangement of the syncing}; and magnetic materials may he more readily under-- stood by reference to the drawing. The conductor 1 is covered throughout its length by the paper-tape 2 and magnetic wrap It pings 3 and 4c oppositely Wound are placed over the paper tape. The .outer layer of magnetic tape may sometimes be omitted- The magnetic tapes are then subjected to a. heat treatment, preferably by passing the of} wrapped conductor through. a suitable furnace at a suitable rate and cooling the coin; ductor at a proper rate after it emerges from the furnace. During the treatment the paper tape is con'ipletely burned away and a small space left between the magnetic tape and the conductor.

A possible explanation of the effective ness of the above process in producing a tie sired permeability at low magnetizing forces in the magnetic material, is that the pres ence of the paper affords the necessary space for the conductor during the expansion and contraction of the conductor and loading material produced by. the annealing treatment. When the magnetic material wound directly upon the conductor, strains and stresses appear to be set up in the magnetic wrap iiing resulting in a lowering of the pern'ieability; hence, the provision of the layer between the conductor and magnetic Wrapping, which may subsequent ly be readily removed, will prevent the strain and stress on the magnetic material. The outer layer ofmagnetic wrapping which is shown in the drawings neednot he separated from the first wrapping by a layer of protective material on account of the fact that the thickness of the magnetic materiai is so small that the two layers may behave as though they were a single layer of twice the thickness.

It is probable also that the difficulty overcome by this invention may be due in part or entirely to the fact that themagnetic material contracts more quickly than the. central conductor during the cooling which follows the heat treatment because of "the intimate contact of the magnetic material. with the cooling medium.

Although the invention has been })tl1tlCl1- larly described with reference to loadin signaling conductors, it is to be nnderstot that it is equally applicable to other a The spacing layer may be removed 7 or during the heat treating operation necessary feature being, that present during; the wrapping ill) ' requires heat treatment to placing a layer heat treatment when netic material, but absent when the space occupied by it is essential to prevent the in etic' material from being brought forcibly into contact with the central conductor duringthe stage or stages of the whatever it may be, comes into play.

What is claimed is: 1. The method of conductor with magnetic material which give it a desired electrical characteristic, which comprises placing a layer of spacing material upon the conductor, placing'the loading material upon the spacing material and subjecting the loaded conductor to the said heat treatment,

the heat of which is great enough to destroy the layer of spacing material.

2. The method of loading a signaling conductor with magnetic material i which requires heat treatment to give it a desired value of permeability, which comprises of paper upon' the conductor, placing the paper, and subjecting the loaded conductor to the Said heat treatment, the heat of which is sufiicient to destroy. the layer ofpap'er.

3. 'The method of loading a signalin conductor with magnetic material whic requires heat treatment to give it high permeability, which comprises wrapping the conductorspirally with paper tape, wrapa subsequently "ductor to the; said heat treatment, the heat ping the magnetic material in the form of tape spirally about the layer of paper, and

subjecting, the loaded conof which is great enough to destroy the layer of paper. r Y i v 4. The method of loading .a signaling conductorwith' magnetic materi l which requires heat treatment to give it a desired electrical characteristic, which comprises placing the conductor, placing the loadin material upon .the spacing material, and'su sequently subjecting the loaded' conductor to the said. heat treatment in an atmosphere which will combine chemically with the layer of'spac- 'ingv material when heated to the temperature necessary for said heat -treatment.

the deleterious action,

loading a signaling loading material upon the a layer of spacing materialupon ntsaeea thickness that when removed the layer of.

loading material, when cold, will fit the conductor fairly closely but not so tightly that strains will be set up therein during said the heat treatment by different rates of ex- I pansion or contraction of the conductor and loading material. I

6. The method of obtaining a desired spacing between an electrical conductor and a mctallic covering therefor, which co1n prises placing a layer of spacing material upon the conductor, placing the metallic covering upon the spacing material, and f:

subsequently subjecting the conductor, so covered, to a heat treatment which destroys the layer of spacing material.

7i'The method of obtaining a desired spacing between an electrical conductor and a coyer therefor of magnetic material, which comprises placing a layer of spacing material u'pon the conductor, placing the magnetic material upon the spacing material and subsequently subjecting the covered conductor to a treatment which will cause the layer of spacing material to disinta grt ate. 8. The method of obtaining the desired spacing between an electrical conductor and a covering therefor of magnetic material which'coinpriscs placing a layer of spacing material upon the conductor, placing the magnetic material upon theispacing, ma-

terial and subsequently removing the spacing material.

In witness whereof, Ihe'reunto subscribe:

my name thislst day bf December A. 1)., 1920.

WILLIAM n rnn Erna..- 

